A formulation primarily used to pitch a show or to quickly sum up the impression a show gives by expressing it as the sum of two separate, unrelated shows. The most famous variation is "DieHardOnAnX", where X is a different location, means of mass transportation, or ''{{IN SPACE}}!'', and so on.

It's very common in music writing -- both reviews and press releases usually describe an artist as "Artist X meets Artist Y". Similarly, a work of literature may be reviewed as being the fusion of the styles of two authors; a common variation is to say that a novel is "as if X had written Y".

See also MixAndMatch, but this differs from it in that, conceptually, MixAndMatch works on the genre level (SpaceOpera + TheWestern = WagonTrainToTheStars), while [=X Meets Y=] works on the show/character level. Should more works/characters be added into the mix (e.g. X + Y + Z...) and it starts specifically using mathematical symbols to define the work/character as parts of others, it becomes {{Troperithmetic}}.

Compare RecycledInSPACE, {{Crossover}}, ThisIsYourPremiseOnDrugs. See also DuelingWorks. Frequent enough with weapons to qualify for a separate trope: see MilitaryMashupMachine. It can also result in a type of [[TropesThatWillNeverHappen/XMeetsY Tropes That Will Never Happen]].